An Egyptian political prisoner has died in a jail in al-Qalyubia Governorate north of the capital city of Cairo, Press TV reports.

The prisoner, named al-Sayed al-Rassd, lost his life allegedly as a result of torture in Banha jail in the Nile Delta region on Monday.

The 46-year-old detainee, who had six children, was arrested by Egyptian security forces on June 4.

According to a report released by the Egyptian Observatory for Rights and Freedoms on Monday, 139 people have died in detention facilities in the Arab country since President Abdel-Fattah el-Sisi took the office in June last year.

The report added that 38 of the deaths took place following the appointment of Egypt’s new interior minister, Magdy Abdel Gaffar, in March.

Overall, 269 prisoners of conscience have died in jails since the ouster of Egypt’s first democratically elected president, Mohamed Morsi, in a military coup in July 2013.

The non-governmental organization stated that 102 of the detainees died inside prisons, 150 inside police stations, 6 inside prosecution and judicial buildings, 2 in military jails, 2 in hospice care centers and 7 in undefined places.

This is while Egypt’s National Council for Human Rights (NCHR), whose members are appointed by the government, only confirmed the deaths of 80 detainees over the past two years.

The NCHR rejected reports by rights groups that the prisoners lost their lives due to torture or deliberate medical negligence, claiming poor sanitary and living conditions, as well as extreme overcrowding of detention facilities are the main reasons of the activists’ deaths.

Sisi is heavily censured by rights groups for launching a heavy-handed crackdown on the supporters of Morsi and stifling freedom of speech in the Arab country. Sisi was the head of the armed forces of Egypt when Morsi was overthrown.

Hundreds of supporters of Morsi and his Muslim Brotherhood movement have been killed and thousands of others detained during Cairo’s clampdown. This is while many of those in custody, including Morsi himself, have received death sentences in speedy mass trials.